1. Field
One or more embodiments described herein relate to a battery module.
2. Description of the Related Art
Various gases (e.g., CO2 and H2) are generated in secondary batteries due to reactions between active materials and electrolytes. When an empty space is formed in a battery due to the formation of gas, inactive regions may be formed on active materials or the movement of lithium (Li) ions in an electrolyte may be obstructed. As a result, the lifespan of the battery may be shortened. Also, when gas accumulates in the battery, the battery may swell, thereby increasing the internal pressure of the battery. Thus, an explosion may occur.
In an attempt to prevent effects, the gas generated in a battery may be externally discharged and bubbles formed in an internal electrolyte solution may be removed. This may allow active materials to function properly. As a result, the safety and lifespan of the battery may be improved.
High-capacity, high-power battery modules have been formed by electrically connecting a plurality of battery cells. In one type of battery module, the battery cells are closely arranged. As a result, when a battery cell deteriorates or gas is generated, neighboring battery cells may deteriorate and/or the safety of the battery module may be markedly reduced, for example, because of thermal runaway. Thus, the occurrence of negligent accidents becomes a possibility.